Nineteen-year-old Irish show jumper Bertram Allen got the perfect start at the World Cup final in Las Vegas when winning the opening speed class with Molly Malone V in the early hours of this morning.

The Wexford rider and the grey mare produced a memorable display when drawn 32nd of 41 of the world’s best riders in the one-round speed class. With a round of poise and power, they turned and twisted in the tight Thomas & Mack Arena to effortlessly shave a second off the time of joint leaders Jur Vrieling from the Netherlands and France’s Patrice Delaveau.

None of the remaining nine riders came close to Allen's target, but his biggest rival proved to be Irish, with the veteran 19-year-old Flexible, bred by Edward Doyle in Co Kildare, coming within half a second in the hands of American Rich Fellers.

Bertram Allen riding Molly Malone V to victory.

The win mirrored Allen's surprise success on the opening day of last year's World Equestrian Games in France, before he ultimately finished seventh.

Reflecting on his latest victory, he said: "I was always going to try to win the class, but for it come off is amazing. I'm very happy with my horse, she jumped super, the atmosphere and the arena were very different but she coped really well with it.”

His 11-year-old mare has a cheeky side.

“Molly is quite a strong character and she has her own special ways. She had me worried earlier today because she half ran away with me when I was riding her, but this evening she knew what she had to do and just went in and did it. She always gives her best.”

The teenager has stunned the sport on his way to Vegas, winning two qualifiers in his debut season and rising to 10th in the Longines World Rankings.

Irish fans are praying the fairytale continues when he goes into tomorrow morning’s two-round second leg and Sunday's Grand Prix aiming to be the first Irish rider to lift the prestigious title.